Effects of High-Pressure Low-Temperature Freezing&Thawing Process on Potato Qualities

Abstract

The research about the high pressure technology to preserve foodstuff has been studied for a longer time, but there were few of papers about the research of the combination effects of high-pressure-freezing&thawing process on food qualities. To examine the combination effects of high-pressure-freezing&thawing process on food qualities, potato was chosen as model object. The experiments were conducted with pressure-shift-freezing processes at 0.1, 100~200MPa, and pressure-assisted-thawing processes at 0.1, 200MPa. Texture analysis was as the key index to evaluate the combination effects of high-pressure-freezing&thawing process on food qualities by Texture Analyzer. At the same time the frozen samples treated by pressure-shift-freezing process were histologically analyzed using the isothermal freezing substitution technique to contrast the pressure effects on the size and shape of ice crystal. The sizes and locations of ice crystals in samples as a result of pressure-shift-freezing were compared to those obtained by atmospheric freezing. The results showed that the combination of pressure-shift-freezing and pressure-assisted-thawing process made less change on the cell wall.